[PATCH AUTOSEL 6.14 486/642] net/mlx5: XDP, Enable TX side XDP multi-buffer support

Sasha Levin
2025-05-05T22:34:30Z

From: Alexei Lazar <alazar@nvidia.com>

[ Upstream commit 1a9304859b3a4119579524c293b902a8927180f3 ]

In XDP scenarios, fragmented packets can occur if the MTU is larger
than the page size, even when the packet size fits within the linear
part.
If XDP multi-buffer support is disabled, the fragmented part won't be
handled in the TX flow, leading to packet drops.

Since XDP multi-buffer support is always available, this commit removes
the conditional check for enabling it.
This ensures that XDP multi-buffer support is always enabled,
regardless of the `is_xdp_mb` parameter, and guarantees the handling of
fragmented packets in such scenarios.

Signed-off-by: Alexei Lazar <alazar@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20250209101716.112774-16-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/mellanox/mlx5/core/en.h | 1 -
.../ethernet/mellanox/mlx5/core/en/params.c | 1 -
.../ethernet/mellanox/mlx5/core/en/params.h | 1 -
.../mellanox/mlx5/core/en/reporter_tx.c | 1 -
.../net/ethernet/mellanox/mlx5/core/en/xdp.c | 49 ++++++++-----------
.../net/ethernet/mellanox/mlx5/core/en_main.c | 29 -----------
6 files changed, 21 insertions(+), 61 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 979fc56205e1f..8f9ec48ecc06d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -386,7 +386,6 @@ enum {
MLX5E_SQ_STATE_VLAN_NEED_L2_INLINE,
MLX5E_SQ_STATE_PENDING_XSK_TX,
MLX5E_SQ_STATE_PENDING_TLS_RX_RESYNC,
- MLX5E_SQ_STATE_XDP_MULTIBUF,
MLX5E_NUM_SQ_STATES, /* Must be kept last */
};

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
index 31eb99f09c63c..8c4d710e85675 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
@@ -1242,7 +1242,6 @@ void mlx5e_build_xdpsq_param(struct mlx5_core_dev *mdev,
mlx5e_build_sq_param_common(mdev, param);
MLX5_SET(wq, wq, log_wq_sz, params->log_sq_size);
param->is_mpw = MLX5E_GET_PFLAG(params, MLX5E_PFLAG_XDP_TX_MPWQE);
- param->is_xdp_mb = !mlx5e_rx_is_linear_skb(mdev, params, xsk);
mlx5e_build_tx_cq_param(mdev, params, &param->cqp);
}

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/params.h b/drivers/net/ethernet/mellanox/mlx5/core/en/params.h
index 3f8986f9d8629..bd5877acc5b1e 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/params.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/params.h
@@ -33,7 +33,6 @@ struct mlx5e_sq_param {
struct mlx5_wq_param wq;
bool is_mpw;
bool is_tls;
- bool is_xdp_mb;
u16 stop_room;
};

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c
index 09433b91be176..532c7fa94d172 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c
@@ -16,7 +16,6 @@ static const char * const sq_sw_state_type_name[] = {
[MLX5E_SQ_STATE_VLAN_NEED_L2_INLINE] = "vlan_need_l2_inline",
[MLX5E_SQ_STATE_PENDING_XSK_TX] = "pending_xsk_tx",
[MLX5E_SQ_STATE_PENDING_TLS_RX_RESYNC] = "pending_tls_rx_resync",
- [MLX5E_SQ_STATE_XDP_MULTIBUF] = "xdp_multibuf",
};

static int mlx5e_wait_for_sq_flush(struct mlx5e_txqsq *sq)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
index 94b2916620873..7a6cc0f4002ea 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
@@ -546,6 +546,7 @@ mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xmit_data *xdptxd,
bool inline_ok;
bool linear;
u16 pi;
+ int i;

struct mlx5e_xdpsq_stats *stats = sq->stats;

@@ -612,41 +613,33 @@ mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xmit_data *xdptxd,

cseg->opmod_idx_opcode = cpu_to_be32((sq->pc << 8) | MLX5_OPCODE_SEND);

- if (test_bit(MLX5E_SQ_STATE_XDP_MULTIBUF, &sq->state)) {
- int i;
-
- memset(&cseg->trailer, 0, sizeof(cseg->trailer));
- memset(eseg, 0, sizeof(*eseg) - sizeof(eseg->trailer));
-
- eseg->inline_hdr.sz = cpu_to_be16(inline_hdr_sz);
+ memset(&cseg->trailer, 0, sizeof(cseg->trailer));
+ memset(eseg, 0, sizeof(*eseg) - sizeof(eseg->trailer));

- for (i = 0; i < num_frags; i++) {
- skb_frag_t *frag = &xdptxdf->sinfo->frags[i];
- dma_addr_t addr;
+ eseg->inline_hdr.sz = cpu_to_be16(inline_hdr_sz);

- addr = xdptxdf->dma_arr ? xdptxdf->dma_arr[i] :
- page_pool_get_dma_addr(skb_frag_page(frag)) +
- skb_frag_off(frag);
+ for (i = 0; i < num_frags; i++) {
+ skb_frag_t *frag = &xdptxdf->sinfo->frags[i];
+ dma_addr_t addr;

- dseg->addr = cpu_to_be64(addr);
- dseg->byte_count = cpu_to_be32(skb_frag_size(frag));
- dseg->lkey = sq->mkey_be;
- dseg++;
- }
+ addr = xdptxdf->dma_arr ? xdptxdf->dma_arr[i] :
+ page_pool_get_dma_addr(skb_frag_page(frag)) +
+ skb_frag_off(frag);

- cseg->qpn_ds = cpu_to_be32((sq->sqn << 8) | ds_cnt);
+ dseg->addr = cpu_to_be64(addr);
+ dseg->byte_count = cpu_to_be32(skb_frag_size(frag));
+ dseg->lkey = sq->mkey_be;
+ dseg++;
+ }

- sq->db.wqe_info[pi] = (struct mlx5e_xdp_wqe_info) {
- .num_wqebbs = num_wqebbs,
- .num_pkts = 1,
- };
+ cseg->qpn_ds = cpu_to_be32((sq->sqn << 8) | ds_cnt);

- sq->pc += num_wqebbs;
- } else {
- cseg->fm_ce_se = 0;
+ sq->db.wqe_info[pi] = (struct mlx5e_xdp_wqe_info) {
+ .num_wqebbs = num_wqebbs,
+ .num_pkts = 1,
+ };

- sq->pc++;
- }
+ sq->pc += num_wqebbs;

xsk_tx_metadata_request(meta, &mlx5e_xsk_tx_metadata_ops, eseg);

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index c748fb07fbd22..1ba133c53fbd9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -2023,41 +2023,12 @@ int mlx5e_open_xdpsq(struct mlx5e_channel *c, struct mlx5e_params *params,
csp.min_inline_mode = sq->min_inline_mode;
set_bit(MLX5E_SQ_STATE_ENABLED, &sq->state);

- if (param->is_xdp_mb)
- set_bit(MLX5E_SQ_STATE_XDP_MULTIBUF, &sq->state);
-
err = mlx5e_create_sq_rdy(c->mdev, param, &csp, 0, &sq->sqn);
if (err)
goto err_free_xdpsq;

mlx5e_set_xmit_fp(sq, param->is_mpw);

- if (!param->is_mpw && !test_bit(MLX5E_SQ_STATE_XDP_MULTIBUF, &sq->state)) {
- unsigned int ds_cnt = MLX5E_TX_WQE_EMPTY_DS_COUNT + 1;
- unsigned int inline_hdr_sz = 0;
- int i;
-
- if (sq->min_inline_mode != MLX5_INLINE_MODE_NONE) {
- inline_hdr_sz = MLX5E_XDP_MIN_INLINE;
- ds_cnt++;
- }
-
- /* Pre initialize fixed WQE fields */
- for (i = 0; i < mlx5_wq_cyc_get_size(&sq->wq); i++) {
- struct mlx5e_tx_wqe *wqe = mlx5_wq_cyc_get_wqe(&sq->wq, i);
- struct mlx5_wqe_ctrl_seg *cseg = &wqe->ctrl;
- struct mlx5_wqe_eth_seg *eseg = &wqe->eth;
-
- sq->db.wqe_info[i] = (struct mlx5e_xdp_wqe_info) {
- .num_wqebbs = 1,
- .num_pkts = 1,
- };
-
- cseg->qpn_ds = cpu_to_be32((sq->sqn << 8) | ds_cnt);
- eseg->inline_hdr.sz = cpu_to_be16(inline_hdr_sz);
- }
- }
-
return 0;

err_free_xdpsq:
--
2.39.5